Machine for producing gear-wheels according to pattern.



H. LEHMANN.

MACHINE FOR PRODUCING GEAR WHEELS ACCORDING TO PATTERN.

APPLICATION FILED MAR 18, 1906.

Patented July 6, 1909.

BSHEETS-SHEET 1.

q wmz ar'; flWM/mm a H. LEHMANN.

MACHINE FOR PRODUCING GEAR WHEELS AGGORDING T0 PATTERN.

APPLICATION FILED MAR.13, 1906.

Patented July 6, 1909.

3 SHEETS-SHEET 2.

FIG. 2.

H. LEHMANN.

MACHINE FOR PRODUCING GEAR WHEELS ACCORDING TO PATTERN.

APPLICATION FILED MAR. 13, 1906.

Patented July 6, 1909.

SSHEETS-SHEET 3.

UNITED STATES PATENT oEEIoE.

HERMANN LEHMANN, OF MAGDEBURG, GERMANY, ASSIGNOR TO FRIED. KRUPP AKTIEN- GESELLSCHAFT GRUSONWERK, OF MAGDEBURG-BUCKAU, GERMANY.

MACHINE FOR PRODUCING GEAR-WHEELS ACCORDING TO PATTERN.

Specification of Letters Patent.

Patented July 6, 1909.

Application filed March 13, 1906. Serial No. 305,831.

For producing the teeth of gear W ieels by planing or milling, it hashitherto been necessary to havea separateset of tem lets on the templet planing process or of mil ing cutters in the rotary cutter or milling process for each tooth-shape and in order to obtain a form of tooth approximately correct mathematically, each set of templets or milling cutters had to consist of from 8 to 12 tools, according to the circular pitch and number of teeth to be produced.

According to the present invention, any pitch and number of teeth can be planed, by means of from 8 to 12 templets, as the number of templets required is only dependent on the number of teeth; the diiierences in pitch being without influence on the result.

This result is attained by having a standard,

which in the present case, is provided with two bits or knives working simultaneously, in which the adjustment of the bits is effected through the medium of a lever, the leverage of which can be adjusted to corre-' spond to the pitch,and one end of which travels on the templet while the other end has controlling connection with the two bit-' holders. The movement of the templet, which determines the position of the bit relative to the work piece, or when two bits are used, the distance between the bits is effected by the carriage upon which the bit holder .ismounted and through the medium of a lever which is likewise adjustable to correspond to the pitch.

\Vith wheels having the same number of teeth, but different circular pitch, it is merely necessary to adjust the two lever proportions to correspond to the itch, the templet however, remaining una tered. If'the pitch is the same while the wheels have different numbers of teeth, the leverages remain unaltered, while the templet must be changed.

The invention is illustrated in the accompanying drawing, in which Figure lis a front view, Fig. 2 a side elevation, and Fig. 3 is a top plan view of my improved machine.

The machine consists mainly of the body 2 slidably mounted on the bed 1, the carriage 5 provided with front and rear dovetail guides 3, 4, and the bitor tool-holders 6 and 7, which are slidably mounted on the front dove-tail guide 3. The lever 9 which is pivoted on the fixed bolt 8, has one of its ends provided with a roller 10 which can travel along the templet 11 and is slotted at its other end to receive a bolt 12, which is adjustable in the slot and can be secured in position therein. On the free end of the bolt 12 is arranged a roller13 which travels in a guide-groove 14 in the bit-holder 6. The slotted part of the lever 9 is provided with a scale for the adjustment of the bolt 12. The two bit-holders are connected with one another through the medium of bolts 15 and 16, hangers 17 and 18, bolts 19 and 20, and a lever 22 which is pivoted on a bolt 21 carried by the carriage 5. A weight 23 on the free end. of the lever 22 tends to move the bits 24 and 25 from each other, but this movement is limited by the templet 11 through the lever connected as aforesaid, with the bit-holder 6.

The templet holder 27 on which the templet 1.1 is secured can be slid in a dove-tail guide 26 in the main body 2. The templet controls the relative positions of the two bits. The templet receives the necessary sliding movement to determine the profile of the teeth from the carriage 5, through the medium of a bolt 28, a link 29, a bolt 30 and a lever 31, swinging on a fixed pivot pin 32. Lever 31 has a slot in which is adjustably secured a bolt 33, carrying upon its free end, a roller 34 which travels in a groove 35 in the carriage 5. ver 31 is provided with a scale.

The support 2 travels to and fro on the bed 1, a distance corresponding to the Width of the wheel to be planed. The length of the fiduciaryedge of the templet is approxi- The slotted part of the le mately equal to the length of working surface of the largest tooth to be obtained; in producing smaller teeth, the entire wor king surface of the same templet exerclses lts influence in determining the profile, but acts through the reducing lever. After each to and fro movement of the entire support, the carriage 5 is moved forward the wldth of a chip, by suitable means (not shown in the drawing). The bolts 33 and 12 having previously been adjusted to correspond to the pitch, or to the ratio between the size of the edge of the templet and the working surface of the tooth, the movement of the carriage 5 is transmitted to the templet holder 27 and the templet 11 by the lever 31 and link 29, in the desired ratio, determined by the location of the bolt 33, and during the forward movement of the attern, while the roller 10 travels up the incline of the temlet, the lever 9 transmits the motion to the bit-holders 6 and 7, in the desired ratio of transmission, determined by the location of the bolt 12.

To impart planing movement to the machine, I may employ the feed screw 6, gear wheels 58, 59, 60, and the reversible belt gear 3645; the reversal of the belt gear be ing effected automatically at the end of each forward and backward movement, through means of the following parts.

Sliding upon the shaft 36, which is journaledat one side of table 1, is an arm 37- carried by the body 2. When the body 2 moves forward, the arm 37 hits the shifting ring 38 on the shaft 36, and moves said shaft with the body 2. Through the belt guides 39,

mounted on the shaft 36, this movement is imparted to belt 41, so that it moves from the driving pulley 40 to the loose pulley 42, and to belt 44 so as to move the latter from loose pulley 43 to driving pulley 45 which reverses the rotation of the feed screw 61, and, consequently, the movement of the body 2. The

belt-shifting device pro er comprises the pivoted lever 46 operated y a projection 48 of a sleeve 49 which is fixed on the shaft 36, the projection being guided in a slot '47 in the ever 46; a rod 50 jointed to the free end of lever 46 and guided in the rotatably mounted block 51, and a spring 52 surrounding said rod 50. When the lever 46 turns, rod 50 moves downward through the block 51 and compresses spring 52 until the lever 46 passes beyond its vertical position at which moment both belts run on the correspondin loose pulleys and the movement of the ody 2 ceases. As the lever passes the position in lme with rod 50, the spring 52 automatically nnparts further swinging movement to the lever 46, and thereby moves the shaft 36 a further distance until the belt 44, which effects the rearward movement of the body 2, is shifted to its corresponding drive-pulley 45.

Toward the end of the rearward movement of the body 2, the arm 37 strikes the shifting ring 64 and moves shaft 36 rearwardly, again reversing the feed screw and through it the movement of body 2, the shifting device acting the same as before, but in reverse direction. The feeding of the bits a distance corresponding to the width of a chip is effected in the following manner: Before the arm 37 can displace the shiftin ring 64, the projection of the ring strires the lever 53 and turns the same together with the lever 55 mounted on the same shaft 54. The movement of the lever 55 swings the weighted lever 56 which by means of a pawl 62 engaging with a ratchet wheel 57 turns the spindle 63, thereby moving the carriage 5, which carries the bits 24, 25, a distance corresponding to the width of a chip.- Thereu on the arm 37 hits the ring 64 and the evice for reversing the movement is actuated. The distance between the two shifting rings 64 and 38 depends on the width of the tooth to be planed.

I do not limit myself to the precise details of construction employed for transmitting motion from the templet to the tool holders and from the carriage to the templet holder, as it is obvious that levers of different orders may be substituted for those shown and the fulcrums of these levers may be located at different points according as the general construction of the machine may require. Obviously, I may also substitute other mechanically equivalent forms of adjustable connections between the levers and the parts with which they are connected and substitute for the tools or tool holders, other known forms or arrangements of these devices.

Having thus described my invention, what I claim as new therein and desire to secure by Letters Patent is:

1. In a templet laning machine, the combination of a mem er adapted to be reciprocated, a tool reciprocating with said member to effect a cut uring the reciprocation of said member, means for advancing the tool as the work progresses, a templet also reciprocating with said member, means transmitting movement from said tool advancing means to the templet, and a connection between the templet and the tool for adjusting the tool to determine the path through which the cutting edge of the tool advances; said connection being adjustable to vary the ratio of transmission of the tool adjusting movement.

2. In a templet planing machine, t e combination of a reci rocating member, a tool suitably mounte on said member and caused to make its out by the reciprocation of said member, a templet also mounted on said reciprocating member and adapted to move thereon in a direction to effect changes in the position of the tool, means through which the temlet adjusts the tool, which is itself adjustab e to vary the ratio of transmission of the tool adjusting movement, means for advancing the tool as its work progresses, and a connection between said tool advancing means and the templet which causes the templet to move as the tool advances, said last-named connection being adjustable to vary the ratio between the movement of the templet and the advancing movement of the tool.

3. In a templet planing machine, the combination of a reciprocating member, a tool suitably mounted thereon to cause the tool to effect a cut during the reciprocating movement of said member, means through which the tool is moved on said member in a direction to advance the tool toward the work, means'through which the tool is adjusted to determine the path of its cutting edge, a templet also mounted on said reciprocating member, a suitably fulcrumed lever controlled by the templet and having connection with the tool, through which it moves the tool in the direction of its adjustment, means through which the tool is moved, and means for varying the relation of the leverage through which the templet controls the lever to that through which the lever imparts the adjusting movement to the tool.

4. In a templet planing machine, the combination of the reciprocating member, a tool suitably mounted on said reciprocating member and caused to make its out by the reciprocation thereof, said tool being mov able on said member to advance it toward its work, and being also adjustable thereon to determine the path through which it advances, a templet having suitable connections with the tool through which it determines the path of the tool, and movably mounted on the reciprocating member, a lever through which advancing movement of the tool is transmitted to the templet to cause it to determine the path of the tool, and means for varying the relative leverage through which said lever transmits said movement.

5. In a templet planing machine, the combination of a body reciprocating to make the cut, a standard movable on the body to produce the feed in making successive cuts, a tool adjustably mounted on said standard to determine the relative positions of the several cuts, a lever through which to move the tool to determine its position during each cut and having an adjustment through which to change the ratio of transmission of such movement, a templet also mounted upon the body of the machine and movable thereon; relatively to the standard, x and means through which the feed movement of the standard upon the body is transmitted to the templet comprising a lever suitably fulcrumed on one of said parts and having suitable connections with the other two and provided with means whereby the leverage through which such motion is imparted may be varied in order to change the ratio between the movement transmitted to the tegnplet and the feed movement of the standar 6. In a templet planing machine, the combination of the body reciprocating to make the cut, a standard adjustable on said body to produce the feed 1n making successive cuts, a pair of tool holders relatively adjustable on said standard, a lever fulcrumed on thestandard and having connections with the respective tool holders on opposite sides ofits fulcrum whereby movement of the lever imparts movement to the tool holders in opposite directions, a lever suitably fulcrumed on the machine and having connection with one of the tool holders through an adjustment which ermits varying the ratio of transmission oi movement, and a templet against which said lever bears, adjustably mounted upon the body of the machine and changing its )osition relatively to the standard in the fee motion of the latter whereby the profile of the templet imparts movement to the lever and determines the position of both outters.

The foregoing specification signed at Magdeburg, Germany this 28th day of February, 1906.

HERMANN LEHMANN.

In presence of- WILHELM FLEISCIIBAGK, JOHANNES SCHIRTTENHELM. 

